The dispersion of gas bubbles in a liquid may be useful for gas-liquid contacting to promote absorption or stripping, with or without chemical reaction, or for foam or froth production. Examples of these include: air sparging to meet BOD (Biological Oxygen Demand) requirements for waste streams; air injection for mixing liquids in a vessel; air sparging to stimulate growth of bacteria for hazardous waste treatment; nitrogen sparging for bulking salad dressings or mustard; CO2 sparging for carbonated beverages and beer; chlorine sparging for bleaching pulp in the manufacture of paper; air sparging for coal flotation and other separations of solids; nitrogen sparging to remove entrained water from motor oil; oxygen or air sparging to enhance cell growth in fermentation reactions; sparging air, oxygen, or other gases into reactors for improved performance; hydrogen sparging for a broad spectrum of chemical hydrogenation reactions; air or natural gas sparging for oil removal from produced water from oil wells; oxygen sparging for bleaching pulp in the manufacture of paper; nitrogen sparging to remove oxygen from edible oils, wine and juices; oxygen sparging in fish farming for stimulation of fish growth; oxone sparging to sanitize ultrapure water systems in pharmaceutical plants; CO2 or NH3 sparging to adjust pH in waste or process streams; direct steam injection for efficient heating, and to eliminate steam hammer; air sparging for removal of VOC (Volatile Organic Compounds) from waste streams; and the like. A problem with many of these operations is that the dispersion of the gas is inefficient.